To create a calm classroom environment as pupils arrive in the morning, introduce Early Morning Work. Pupils enter the room, follow the directions on the board, and work on the task they have been directed towards.
Ideas for EMW:
Basic maths operations
Write down an adjective for every letter of the alphabet
Countdown maths or letters
Countdown conundrum or anagram
EMW can be organised to suit any age group and fit in with your curriculum. You may want to encourage participation by rewarding pupils for participation using a reward system that they are engaged with. Pupils could complete tasks on a mini whiteboard or book to keep track of their EMW. You may just want them to complete tasks in their rough books or something similar.